The present invention is in the field of envelope forming machines and is more particularly directed to an envelope forming machine for forming open end envelopes having an end flap to which contact adhesive is applied with a patch release paper being applied over the adhesive to protect and preserve the adhesive until such time as the envelope is ready to use.
Previously known envelope machines of the type manufactured by F. L. Smithe Machine Company, Inc. of New York, N.Y., employ a frame supported envelope blank feed means for feeding envelope blanks through a series of work stations in which operations such as scoring, folding, and the like are performed on the envelope blanks to form the complete envelope which is then discharged at an envelope delivery station at the downstream end of the machine. The envelope blanks are received from an infeed conveyor and pass in succession past a blank re-feeder at the upstream of the machine, a first aligner, a printing station which includes a selectively operable transfer roller which when operated serves to direct envelope blanks downwardly into printing means positioned below the normal feed path for applying desired indicia to the envelope blank which is then returned to the normal feed path. The partially formed envelope then moves past a second aligner and side flap score and fold station and is then shifted laterally through end flap score and fold means and thence to an envelope delivery station from which the completed envelopes are discharged.
When conventional apparatus of the foregoing type is used for forming open end envelopes having an open end flap to which adhesive and an overlying patch of release paper are applied, the adhesive is applied to the envelope blanks at a station at the upstream end of the infeed conveyor with the blanks then moving the length of the conveyor from which they are fed past the blank re-feeder, the first aligner, the printing station, the second aligner, a release paper patch applying apparatus positioned and located between the second aligner and the side flap score and fold station. The adhesive on the end flap is consequently unprotected as it moves along the feed path of the machine over the printing apparatus so that the adhesive sometimes contacts parts of the machine or other envelopes to create waste and possible jamming of the machine along with an undesirable and unsightly accumulation of adhesive on parts of the machine. In order to minimize the accumulation of adhesive on the machine, it has consequently been the practice in the industry to apply powder in the form of cornstarch over the machine surfaces most likely to be brought into contact with the adhesive so as to create a dusty and somewhat unsightly operation. Moreover, in order to minimize the amount of wastage, it is necessary to operate the machine at a relatively slower speed than would otherwise be possible.
Therefore, it is the primary object of the present invention to provide a new and improved envelope forming machine for forming open end envelopes having an end flap coated with contact adhesive and a protective release paper patch applied over the adhesive.